When Apple makes headlines for its manufacturing practices, it’s rarely a headline that makes Cupertino look good. The company has come under fire in the past year for its reliance on the manufacturing giant Foxconn, which had a string of suicides at one of its plants, and where there have occasionally been reports of unsafe working conditions. The New York Times, for instance, wrote an investigative report into the “human costs” of the iPad back in January; iPhone manufacture even became the unlikely subject of a controversial, and ultimately discredited, work of quasi-reported theater (see “Mike Daisey, Storyteller,” and “An (Actual!) Look Inside Foxconn”). But for those who thought Apple would continue to exclusively rely on manufacturing abroad, Apple CEO made a surprising announcement on “Rock Center with Brian Williams” today. Starting in 2013, said Cook, a line of Macs would be manufactured in the US. Cook did not elaborate or specify just which line.

The announcement followed recent reports that some of the new iMacs that went on sale last Friday bore the unusual words, “Assembled in USA.” In the past, it has been more typical to see “Assembled in China”–though not uncommon for certain products, like made-to-order Macs.

In a way, Cook’s announcement is not totally surprising; at the All Things D conference in May, he had announced that he wanted a product to be made in the U.S. It would seem like the recent “assembled in USA” lines are a step in that direction, and that Cook is planning to deepen that commitment.

A good deal more information about Cook’s thinking in this regard can be found in Bloomberg Businessweek, which published a lengthy interview with Cook this week. Cook pointed out (as he did to Brian Williams) that both the processor and the glass on iPhones and iPads are made in the U.S. (See “Your iPhone’s Brain Might Be from Texas.”) And he clarified that when he says he’d like to “make” Macs in the US, he’s talking about more than assembly:

“It will happen in 2013. We’re really proud of it. We could have quickly maybe done just assembly, but it’s broader because we wanted to do something more substantial. So we’ll literally invest over $100 million. This doesn’t mean that Apple will do it ourselves, but we’ll be working with people, and we’ll be investing our money.”

A follow-up question on whether Apple had a duty to be patriotic elicited a thoughtful response: Cook said that he felt Apple did have a “responsibility to create jobs.” He appeared to outline a philosophy that suggested that Apple had that responsibility, indeed, wherever it sold its products: “Over 60 percent of our sales are outside the United States. So we have a responsibility to others as well,” he said. He chooses a more holistic way of measuring job creation, which means that he considers a person who makes a living as an iOS developer to have had a job created by Apple, even if that person is working for herself. (Again in its iEconomy series, the Times has shown how making that living is sometimes easier said than done.) The Businessweek interview is required reading in full for anyone interested in Tim Cook, Apple, and the future of American manufacturing.

Meanwhile, Bloomberg also reports that Foxconn itself will be expanding some of its manufacturing operations into North America, due to demand among customers that more products be made domestically.